Fluid-pressure brake.



N0- 797,542. I PATENTED AUG. 15, 1905. H. H. WESTINGHOUSE & F. L. GLARK.

FLUID PRESSURE BRAKE.

APPLICATION FILED 1330.15. 1903 2 SHEETS-SHEET 14 ydd I Atty.

:munaw & cnmm co, Pnommnosmwms. wnsnwarou. 0 c.

No. 797,542. PATENTED AUG; 15,1905.

H. H. WESTINGHOUSE & P. L. CLARK.

FLUID PRESSURE BRAKE.

APPLICATION FILED DEG; 15, 1903 2 SHEETSSHEET 2.

9.4.4 MM 1; MW

NlllElli S'lUrtiillES PA'illllE; 'Tli HENRY H. W ESTINGHOUSE AND FRANCIS L; CLA BK, OF PITTSBURG, PENN SYLVANIA, ASSIGNORS TO THE WESTINGHOUSE AIR BRAKE COMPANY, OF PlT'lSBURG, PENNSYLVANIA, A (lOl-KLPORA'IION OF PENNSYLVANIA.

FLUlD PFiESEURlE EEFMMME.

Specification of Letters Patent.

Patented Aug. 15, 1905.

Original application filed November 9,1899, Serial No. 736,422. Divided and this application filed December 15,1903. Serial No. 185,283.

To (017/ 1117110777, it nil/,7 concern:

Be it known that we, linker lil \Vns'rrNenoose and FRANCIS L. CLARK, citizens of the United States, residing in Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a certain new and useful Improvement in Fluid-Pressure Brakes, of which the following is a specification.

This invention relates to fluid -pressure brakes, and has for its principal object to provide an improved feed-valve device for automatically controlling the supply of fluid under pressure from the main reservoir to the train-pipe when the engineers brake-valve is in running position, as set forth in our prior application, Serial No. 736,t22, filed November 9, 1899, of which this present application is a division. Heretofore valve devices employing a puppet-valve actuated directly by a diaphragm subject to the opposing pressures of the train-pipe and an adjustable spring, such as shown in Westinghouse Patents, Nos. 557,463 and 561,949, have been used 'for this purpose; but in these prior devicesit has been found diliicult to regulate the train-pipe pressure as closely as desired, for the reason that when the valve is open its entire area is exposed to fluid-pressure on its opposite sides, but when closed upon its seat the valve is held closed by an excess of pressure on the mainreservoir side, due to the area of the valve where it engages with its seat, which causes quite a difference in the degree of train-pipe pressure required to close the valve from that at which the valve will open and making its operation uncertain. Furthermore, this oldstyle valve was liable to become leaky on account of accumulation or lodging of particles of dust or dirt upon its seat, which resulted in the overcharging of the train-pipe or the inadvertent release of the brakes. It has also been found that with the prior device the feeding of the train-pipe was very slow when the train-pipe pressure had risen to nearly normal pressure on account of the train-pipe pressure acting on the diaphragm being suliicient to partially compress the spring and nearly close the feed-valve, so that it often required a comparatively long period of time to feed the train-line up the last few pounds to the closing point of the valve at normal train-pipe pressure. These dil'liculties are avoided by means of our present improvement, which embodies a slide-valve pressed to its seat by nmin-reservoir pressure and operated by a piston normally exposed on one side to mainreservoir pressure and a small valve governed by variations of train-pipe pressure for controlling the release of fluid from the opposite side of said piston.

Another feature of our invention com prises means for supplying liuid under pressure from the main reservoir to the feed-valve chamber when the engineers brake-valve is in full release position, in which a direct port is open from the main reservoir to the train-pipe for the purpose of balancing the fluid-pressure upon the slide-valve of the teed-valve device and prevent the same from being lifted from its seat.

In the accompanying drawings, Figure 1 is a view, partly in section,showing an enginee1"s brake-valve and feed-valve device constructed in accordance with our invention; Fig. 2, a horizontal section taken on the line a: of Fig. 1; Fig. 3, a plan view oi. the rotary valve of the engineefis brake-valve; Fig. i, a central longitudinal section of the feed-valve device detached; and Fig. 5, a view, partly in trans verse section, taken at right angles to Fig. 4:.

As shown in the drawings, the casing 1 of the automatic feed-valve device is secured to the. casing 2 of the engineers brake-valve in such a position that the passage 3 of the casing 1 registers with the passage st of the casing 2, which communicates with the main reservoir through a port in the valve-seat and through a port 5 in the rotary valve 6 when that valve is in running position. The passage 7 in the casing l registers with a passage 8 in the casing 2, which is in communication with the train-pipe just below the direct applieation and supply-port 9. \Vhen the handle of the engineers brake-valve is in running position, fluid under pressure is admitted from the main reservoir through the passage 5 in the rotary valve and through the port 33 and passages a and 3 to a passage or space 1.0 and to the slide-valve chamber 11 in the eas- -ing 1 of the feod-valve device, and the slide valve 12 is exposed to main-reservoir pressure, tending to hold the valve to its seat.

The slide-valve 12 is preferably provided with wings 13, which project upward on each side of the stem ll of a movable abutment or piston 15, the wings being fitted between shoulders 16 and 17, so that the valve will be moved whenever the piston is moved in either direction. The piston 15 is located in a chamber 18, which is closed at one end by a cap-nut 19, and a spring 20 bears at one end on the piston and at the other end on the capnut and tends to move the piston and feedvalve 12 into position to close the port 21 in the valve-seat. \Vhen the piston 15 and the feed-valve 12 are moved to the right, so as to uncover the port 21, the port 21 forms a communication between the passage 10 and a passage 22, which connects through the passages 7 and 8 with the train-pipe. A passage 23 connects the passage 22 with a chamber 24, which is closed on one side by a movable abutment or diaphragm 25, which is adapted to be moved in one direction by an adjustable spring 26 and in the other direction by the trainpipe pressure above it in the chamber 24. A small regulating-valve 27 controls a passage 28 between the diaphragm-chamber 24 and a chamber or space 29, which communicates through a passage 30 with the piston-chamber 18. The movable abutment or diaphragm 25 is at all times exposed on its upper side to the pressure in the train-pipe, the chamber 24 being in open communication therewith through the passages 23, 22, 7 and 8, and when the desired maximum pressure exists in the train pipe the diaphragm 25 will be moved downward out of contact with the stem of the valve 27, thereby permitting closure of the valve 27. hen the brake system is not charged with fluid under pressure and the piston 15 is not exposed on either side to fluid under pressure, the spring 20 will hold the piston 15 'in the position shown in Figs. 1 and 4 of the drawings, and the slide-valve 12 will then cover the port 21. When the rotary valve 6 of the engineers brake-valve device is in running position, fluid under pressure will flow from the main reservoir through the port 5 in the rotary valve and through the passages4, 3, and 10 to the slidevalve chamber 11, and the back of the slidevalve 12 and theleft-hand side of the piston 15 will be exposed to main-reservoir pressure. A leakage of fluid will take place around the piston 15 into the chamber 18 on the right of the piston, and so long as the small valve 27 is closed the piston 15 will be exposed on both sides of equal areas to main-reservoir pressure and the spring will hold the slide-valve in its closed position. If the pressure in the train-pipe falls below the desired normal maximum pressure, which is usually about seventy pounds, the spring 26 will raise the diaphragm 25, and by contact with the stemof the small valve 27 that valve will be unseated and, a communication established between the chamber 18 and the train-pipe through the passages 30 29 28, chamber 24, and passages 23, 22, 7, and 8. Fluid under pressure will then flow from the chamber 18 to the train-pipe, and the main-reservoir pressure on the left of the piston 15 will move the piston 15 and the valve 12 to the right, so as to open the port 21, which will permit fluid under pressure from the main reservoir to flow to the train-pipe until the train-pipe pressure and the pressure in the diaphragmchamber 24, reaches the desired maximum, when the diaphragm will be moved down against the pressure of the spring 26 and the small valve 27 will be seated by the spring 31. Fluid under pressure from the main reservoir will then leak around the piston 15 until the pressure on the right of the piston in the chamber 18, together with the pressure of the spring 20, is great enough to overcome the main-reservoir pressure on the opposite side and move the valve 12 to the left, so as to close the port 21. The port 21 will remain closed until the pressure in the train-pipe and in the chamber 24 again falls below the maximum, when the diaphragm will again be raised and the small valve 27 unseated to permit the pressure on the right of the piston 15 to flow to the train-pipe, when the piston 15 and valve 12 will again move to the right and open the port 2l to admit fluid from the main reservoir to the trainpipe until the train-pipe pressure and the pressure in the chamber 24 again reach the maximum, when the diaphragm will be moved down and the small valve 27 closed, so as to permit an accumulation of pressure from the main reservoir iu the chamber 18 and the closing of the valve 12.

In order to charge the slide-valve chamber 11 with fluid from the main reservoir when the rotary valve 6 is in the full release position and when the train-pipe is being charged directly through the port 34 in the rotary valve and the port 9 in the valve-seat, we provide in the rotary valve a small port 32, which before the rotary valve 6-is moved to the running position.

It will now be seen that by using thesmall diaphragm-valve for controlling the release of air from the chamber 18 back of the piston which actuates the slide-valve the same may be made to open and close at substantially the same degree of train-pipe pressure that is, it will require only a slightly greater degree of train-pipe pressure upon the diaphragm to secure the closing of the small valve 27 than that which is overcome by the spring 26 acting on the opposite side of the diaphragm to cause the small valve to open, thus securing teams the opening and closing of the slide-valve at substantially the same train-pipe pressure, and thereby maintaining in the train-pipe a substantially constant degree of pressure when the engineers brake-valve is in running position. Another important advai'itage resulting from the use oi this small diaghragmvalve is that but a slight range ol pressure is required to move said valve from its open position to closed position, whereby the main slide-valve may be held nearly to its full opening until the train-line is fed up nearly to normal pressure, thus avoiding the slow feed and delay in charging up the train-pipe the last few pounds to standard normal pressure and insure a prompt and positive closing of the feed-valve when that pressure is attained. It will also be evident that by the use of the slide-valve held to its seat by main-reservoir pressure and reci irocated by the piston the valve-seat will be kept bright, free from dirt,

. and perfectly tight, thereby in'eventing any possibility of leakage from themain reservoir to the train-pipe through the feed-valve when the same is closed. As the piston for actuating the slide-valve has equal areas exposed to fluid-pressure on its opposite sides, it requires only a slight opening of the regulating-valve to produce suflicient difference in the opposing pressures to cause the opening oi the feedport, thereby rendering the device very sensitive and adapted to open upon the slightest reduction in train-pipe pressure due to leakage, whereby the train-line will be constantly maintained at the normal standard. pressure while the engineers brake-valve is in running position.

Having now described our invention, what we claim as new, and desire to secure by Letters Patent, is

1. In a flUlCl-DIGSSEH'O brake, the combination with an engineers brake-mlve, of a valve device for regulating the pressure in the trainpipe, and means whereby pressure from the main reservoir is supplied to said feed-valve device when the engineers brake-valve is in release position.

2. In a fluid-pressure brake, the combinationwith a feed-valve device for regulating the pressure in the train-pipe, of an engineers brake'valve having a feed-port for sup ilying fluid under pressure from the main reservoir to the feed-valve device when the engineefis brake-valve is in running position, and another port for supplying lluid to the said valve device when the engineers brake-valve is in release position.

3. In a fluid-pressure brake, the combination with a feed-valve device having a valve adapted to be. held to its seat by main-reservoir pressure and exposed on its opposite side to train-pige pressure, of an engineers brakevalve having means for admitting fluid from the main reservoir to said feed-valve when the engineers brake-valve is in release position.

st. In a fluid-pressure brake, the combination with a feed-valve device having a slidevalve for regulating the supplyof fluid under pressure from the main reservoir to the trainpipe, of an engineefis brakevalve having a port for admitting fluid from the main reservoir to said slide-valve when the engineers brake-valve in release position.

In a lluid-pressu re brake, the combination with an engineers brake-valve having a t'eedpassage adapted to communicate with the main reservoir, and a train-pipe passage, of a feed-valve casing having two openings communicating respectively with said pas sages, a slide-valve and piston within said casing and exposed on one side to pressure of fluid from the main-reservoir passage, said piston having equal areas exposed to lluidpressure on its opposite sides, a spring nor mally tending to move said slide-valve to its closed position, a diaphragm subject to the opposing pressures of the train-pipe an adjustable spring, and a valve operated by said diaphragm for controlling the release of fluid from the opposite side of said. piston.

6. In a fluid-pressure brake, the combination with an engineers brake-valve having a feed-passage adapted to communicate with the main reservoir, and a train-pipe passage, of a feed-valve casing having two openings communicating respectively with said passages, a chamber provided with a valve-seat at one side thereof and a port in said valveseat, a passage leading from the main reservoir opening to the valve-chamber, another passage leading from said port in the valveseat to the train-pipe opening, a slide-valve and piston located in said chamber and exposed on one side to main-reservoir pressure, said piston having equal areas subject to fluid pressure on its opposite sides, a spring normally acting to move said valve to its closed position, and a valve governed by the trainpipe pressure for controlling the release of fluid from the opposite side 0] said piston.

7. .In a fluid-pressure brake, the combination with an engineefis brake-valve of a feedvalve device having a slide-valve for controlling the supply of liuid from the main reservoir to the train-pipe when the engineei"s brake-valve is in running position, a piston having equal areas exposed to fluid-pressure on its opposite sides for operating said slidevalve, a spring normally acting to move said slide-valve to its closed 'iosition, a regulatingvalve for controlling the li aid-press u re on one side of said piston, and a diaphragm subject to the opposing pressures of the train-pipe and an adjustable load device for operating said regulating-valve.

8. in a iiuid-pressure brake, the combination with an engineefls brake-valve of a feedvalve device having a slide-valve for controllingthe supply of fluid from the main reservoir to the train-pipe when the engineei"s brake-valve is in running position, a piston exposed on one side to main-reservoir pressure for operating said slide-valve, said piston having equal areas exposed to fluid-pressures on its opposite sides, a spring normally acting to close said valve, a regulating-valve for controlling the release of fluid from the opposite side of said piston, and a diaphragm subject to the opposing pressures of the trainpipe and an adjustable spring for operating said regulating-valve.

9. In a fluid-pressure brake, the combination of a slide-valve for controlling the supply of fluid under pressure from the main reservoir to the train-pipe, a piston exposed on one side to main-reservoir pressure for operating said slide-valve, a spring normally acting to move said valve to its closed position, a passage leading from the chamber on the opposite side of said piston to the train-pipe, and a regu lating-valve governed by variations of trainpipe pressure for controlling said passage.

In testimony whereof We have hereunto set our hands.

HENRY H. WVESTINGHOUSE. FRANCIS L. CLARK.

WVitnesses:

R. F. EMERY, JAs. B. MACDONALD. 

